Marky Market gets up at 2am so you don't have to

I've only been doing this for three years. I was made redundant in 2009 – I'd been a copywriter for 20 years. After wasting six months looking for another job in ad land, I started helping out an old mate, Johnnie Mountain, at his north London restaurant Mosaica: kitchen portering, washing-up, prepping veg, that kind of thing. It was only £20 a shift, but I found that I loved working with food.

I started going with Johnnie to the markets – Billingsgate, Smithfield, Covent Garden – and found them fascinating: the characters, the sheer quantity and quality of the produce, the history, everything. Anyway, Johnnie hated getting up early, so I started going for him. Then one day, at my local fishmonger, it hit me. They were selling sardines for more than twice what I'd paid that morning at Billingsgate, and I realised there might be a way to make a living out of this.

I had no capital – just debts – so I borrowed £20, spent it on sausages, turned that into £35, and it grew from there. I branded myself as Marky Market, "your man at the market" (the years in advertising weren't totally wasted), set up a website and word-of-mouth and social media did the rest.

I set the alarm for 2am, pick up a vehicle from the Zipcar car club (there's always one available at that time), drive to Smithfield and Billingsgate, and buy whatever my customers have ordered from me. That early, you get the pick of the produce, and have time for a proper chinwag. They call me Big Time at Smithfield, because I buy so little compared to the retailers, but one of the butchers gave me a white coat the other week – that's when you know you've been accepted.

I get home around 6am, box everything up into individual orders, then hit the tubes and buses to make my deliveries. I carry it all around on an old market trolley. I can get up to 45kg on there, though that's my limit – you try lugging around more. I deliver to people's offices in central London, plus the occasional house call.

I don't earn that much, but I've got more freedom than most, and enough in the bank to pay the bills and buy a pint, which does me. Anyone could do this, but the thing is, who wants to get up at 2am?

Venison and black pudding stew

This is something I made a couple of weeks ago. I'd been lumbered with some diced venison – it comes in 2.5kg bags at Smithfield, and I'd had orders for only 1.75kg. The black pudding adds flavour and thickens the sauce.

1 Heat the oven to 150C/300F/gas mark 2. Heat the oil in a heavy casserole dish on a high heat. Roll the venison in seasoned flour, shake off any excess, and brown in batches, transferring each lot to a plate before adding the next.

2 Turn down the heat, and sweat the onion, garlic and carrot in the same pan until the onions are translucent (you may need to add a little more oil). Add the rosemary and bay, cook for two minutes, then return the venison to the pan along with the black pudding.

3 Add the wine, bring to a steady boil and reduce by half, then add the stock and chestnuts, and bring to a simmer. Season, pop on a lid and stick in the oven for at least two hours. That's it.

• This article was amended on 19 February to make it clear that Mark does not buy meat from Covent Garden market, which is a wholesale fruit, vegetable and flower market.